Search results for "Vacuum permittivity"
showing 3 items of 3 documents
Relation of Dielectric Permittivity and Electric Field Dependence of Polarization in Some Relaxors with Perovskite Structure
2011
The dielectric nonlinearity is studied in ferroelectric relaxors 0.92PbMg1/3 Nb2/3O3-0.08PbTiO3, 0.4Na1/2Bi1/2TiO3-0.5SrTiO3-0.1PbTiO3 and Pb0.9075La0.0925 (Zr0.65Ti0.35)0.9775O3. It is shown that above the temperature of dielectric permittivity maximum nonlinearity of dielectric permittivity corresponds to electric field dependence of polarization. The influence of electric field on distribution of relaxation times is studied below the maximum of dielectric permittivity. The role of internal bias field in Pb0.9075La0.0925(Zr0.65Ti0.35)0.9775O3 ceramics is discussed.
Accurate determination of the complex permittivity of materials with transmission reflection measurements in partially filled rectangular waveguides
2003
An enhanced transmission reflection technique for the precise determination of the complex permittivity of dielectric materials partially filling the cross section of a rectangular waveguide is described. Dielectric properties are determined by an iterative procedure from two-port S-parameter measurements and a numerically generated propagation constant obtained from the analysis of a partially filled waveguide. Convergence of the solution is ensured from perturbational approximations. Unlike previous approaches, an uncertainty investigation is performed, taking into account all the parameters involved in the dielectric characterization. Permittivity accuracy values are presented and, hence…
Evolution of dielectric permittivity under applied field in PLZT 8.3/70/30 ceramics
2000
Abstract The jump of dielectric permittivity as function of bias field applied after various duration of storage at the measurement temperature is investigated. The influence of storage time on ϵ(E=) depends on the value of bias field and frequency of measuring field. It is found that ϵ(E=) depends on the path of how particular field value is reached.